Hot-blast stove



' (No Model.) v 3Sheets-Sheeiz1, J. M. HARTMAN.

HOT BLAST STOVE.

Patented Feb. 28,1882.

v No. 254,131.

(No Model.)

J. 3 Sheets-Sheet 2.

HOT BLAST STOVE.

No. 254,131. Patented Feb. 28,1882.

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WITNESSES.

(No Model.) 3 Sheets-Sheet a.

J.M.HARTMAN.

HOT BLAST STOVE.

No. 254,131. Patented Feb. 28,1882.

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-UNITED; STAF-Es' OFFICE.

JOHN -M..-HARTMAN, OF PHILADELPHIA, PENNSYLVANIA.

HO T.- BLAST .s'rov E.

.-'.SPECIFICATION forming part of Letters Batent N0. 2t' 4,132l,=dated February 28, 1882.

Application filed .November 10, 1880. (N0 model.)

To'all whom it may concern 1136 it known that l, J OHN M. HARTMAN, a citizen of the UnitedStates, residingat Phila- "del-phia, State of Pennsylvania, have invented 5-new and useful Improvements in Hot-Blast "Stoves, of which the following is a specification. :The' objeet of this invention is improved meansv for heating air or gas.

lheinventionconsists in the construction and improvements hereinafter enumerated: first,iu the construction of the foundationsuprporting the-stoves; second, in the method'of cleaningthestoves; third, operating thetvalves of thestoves*with pistons operated by air, steam or water fourth, combining the valves, znozzles,andinletsinone casing; fifth inducing acirculationof water throughthecooling- -passages of thevalves bysuction I attaiu these objeetsby apparatus illustrated in the drawings, in which- 7 f Figure l shows plan of new foundation, stoves, and pipes. Fig. 2-shows end elevation of stovesand pipes and; the foundation in section. Fig. 3-shows a vertical section of stoves with the passages and combustion-chamber.

:Fig. 4 shows a horizontal section of-passa es and combustion-chamber. Figs. 5, 6, 7 i plugs or-stoppers for the regenerator openi lF ig"; 8 shows elevation of. compound nozzles tion apparatus.

Similar letters refer tosimilar parts through- ;outthe-zseveral' views. 1

In operatingregenerative stoves the gas to .heatthem is admitted to the combustion-chamber C, Fig. 8, through the valve K, Figs. land :8, and the air toburn the-gas is admittedthrough 40..

the: door FyFig. 8. "The productsof combustion then pass up the chamber 0, down through :the -regenerator-;passages i D- D D, Fig. 4, and eescape. atrzthe vehimney valve A. After the- -:-;:stove.':is heated-upthe valves A- K F are closed less.

zandztherhot -blastvalve K and the cold-blast. :valve' -E:are.ope,ned whichuadmits air-to the:

stove 'andrthenee tothefurnace.

Heretofore regenerative stoves have had:

' it-heir flues-.conveyingfthegas to andfrom the s rastoves built in I theifoundation outside 1. orbe- "to' remove the-dust.

yond theouter line of the stoves, which makes a wide, costly foundation. To overcome this I place the flues B -B, Fig. 2, under the stoves and lessen the width of the foundation. By this means the walls forming the flues support the stoves and convey the gas also. I am aware that flues have been built in foundations under coke-ovens.

The gas used to heat the stoves is freighted with ashes, which collect on the sides ofthe passagesD D D and choke them. Owingto the slowness of the current of gas through the passages D D D, the gas-ashes collect rapidly and require frequent stoppages for cleaning them. :Each passage D D D is. independent and surrounded on all sides by continuous brickwork, each brick forming part of four separate ;passages,which givesthe greatest possible heating-surface in the least space.

Cleaning the passages D D D of a regenera-' tor-with a brush is a slow, diffieult process, and :in many cases, owing to the smallness of the passages, the brush-jams in them and will not pass-through. This passage then becomes use- To clean the stoves by blowing through thewhole'regenerator-at once the current of airpasses too slowly to remove the dust. By

. building the checker-work to form continuous independent passages and stopping off at the top, as .shownin Figs. 3 and 4, say, threefourths of the openings with plugs, as in Figs. 5, 6, and 7, the blast is concentrated and *blown through the balance of the openings with sufficient .velocity to remove the dust. Then by shifting part of the plugs to the clean eholesthe-air will be blown through'the holes theplugs are taken from, which will clean them. By alternately shifting the plugs and blowing the stoves are thoroughly; cleaned. Cleaning the stoves by a jet of air..blown i through a single opening, the pressure of blast islo'st or d-issipated by the leakages through the walls forming the passages of the regenerator, and cannot be kept concentrated enough In my method the whole regenerator is filled with blast under pressure, and noescape takes place except through the openings that are not stopped off.

I- do not confine myself to a particularform or" method of closing the top of the regener-' ator while blowing through, as herein described. p

I am aware that attempts have been made to clean these stoves by thrusting a pipe in sections down through the regenerator openings, through which pipe a sharp current of blast was blown. Heretofore various devices of chains, drums, sheaves, and screws have been used to operate the valves of regenerative stoves. I prefer to use cylinders with pistons, as at G G, Fig. 8, attached to the valve-disks to operate them. The pipe H, Fig. 1, for supplying the air to these cylinders is attached to the main cold-blast pipe I of the furnace. IVhen the supply of air is cut off from the blast-furnace the pressure of gas in the interior of the furnace forces the gas back through the hot-blast pipe connecting the furnace to the stoves and fills the stoves with gas. This gas, being carbonic oxide and hydrogen, fires, explodes, and destroys the stoves. By using the cylinders G G, Fig. 8, having their pistons V V attached to the stems or rods X X, and attaching the rods X X to the valvedisks S S, then connecting the cylinders at T T with a pipe, H, to the main cold-blast pipe I, as shown, the pistons and valves are raised by the pressure of blast orair when itis put on the furnace. As soon as blastis taken off from the furnace the pressure ceases under the pistons V V, and the pistons, with the valvedisks, drop and close the valves, thereby cutting off the back flow of gas and avoiding explosions. By this arrangement I combine with the valves of a regenerative stove ameans of operating them, which also acts automatically and cuts off the back flow of gas. As these valves are operated between the time of throwing blast off and on the furnace, suitablecocks or valves are placed at the bottom of the cylinders and connected in the pipe conveying the air to the cylinders and pistons.

The pistons can be operated by air, steam, or water; but I prefer the air from the blowing-engine.

The cold-blast valve E, being horizontal, is operated with a double-acting cylinder, and does not operate when blast is thrown off the furnace.

The valve for throwing blast off and on the furnace is placed in the cold-blast pipe I, between the stoves and the blowing-engine.

I am aware that surging-valves have been used in cold-blast pipe, which valves were operated by pistons,asin the patent of H. Davies, 113,745,April13, 1871; but in this case the gas would back into the stoves, as the valves are not placed between the furnace and the stoves.

I am also aware that it has been proposed to place the above surging-valves in the hotblast pipe between the furnace and the stoves, but there being no provision made to cool the valve, it would soon be destroyed by the high heat from the regenerative stove. p 1 i I do not broadly claim an automatic valve for cutting off the back flow of gas from a furnace; neither do I claim a water-cooled valve in combination with a regenerative stove.

I do not confine myself to a certain position of the hot-blast valve K, as it can be made separate and placed nearer the furnace.

Heretofore valves and nozzles for regenerative stoves have been made in separate pieces. This makes extra joints, a greater number of separate attachments to the stove, and increases its cost. To obviate this I combine two or more nozzles and valve bodies or valves, K K, and inlets F P in one casing, as at R, Figs. 8, 9. By this combination three or more separate attachments are made in one piece and a better pipe arrangement is obtained.

In opcratin g regenerative stoves the valves are subjected to an intense heat, and are cooled with an internal circulation of water under pressure to keep them to shape and prevent the leakage of gas or blast. At times these valves crack and leak water into the furnace, which chills the hearth and stops its operation. This water also forms hydrogen gas, which has exploded and caused a large loss of life and property. To obviate this I draw the cooling-water through the pipe J J W W, Fig. 8, in the valve disks and bodies by putting it in astate of tension or'below the atmospheric pressure in the disks and bodies. If a valve cracks with the water in tension, there will be no leak of water into the hotrblast pipe or stove. The pipe Z Z supplies the valvedisks with water. The pipe W W passes through the pipe Z Z over the top of the cylinders, leaving an annular space between the inner and outer pipe, through which the water flows to cool the disks.

The water can be put in tension by a. pump, W, or a pipe with a low outlet. 1

I am aware that the discharge-water pipe of the valves of a regenerative stove has been carried down to the bottom of the stove before discharging the water; but to induce a proper circulation I carry it not less than three feet below the bottom of the stove when pumps are not used.

I claim- 1. In combination with an air-tight regenerative stove, an external foundation having in it the flue B for conveying the unburned gas to the stove and the flue B for conveying the burned gas to the chimney, the said flues being placed under the stoves, and the connections from the stoves to the fluesbeing 4 external to the stoves.

2. The method of cleaning the passages of a regenerative stove, which consists in stopping or closing part of the passages and discharging a current of compressed air through the remaining passages, whereby the air-blast is concentrated in the open passages and a thorough cleaning is obtained.

3. In combination with a regenerative stove having watercooled valve-disks S S, the cylinders G G, the pistons V V, the piston-rods g i, and pipe T T, for operating the valve- 4. In combination with a regenerative stove, a compound nozzle containing the valve-bodies 5 K K and one or more openings, F P, into the stove.

5. The combination, with the valves and their seats, of a regenerative stove, the valves and valve-seats being provided with water-circulating passages, an education-pipe, and exhaust- 1o ing device, whereby a circulation of water is induced through the said passages by suction.

JOHN M. HARTMAN. Witnesses:

J. H. FRIES, HARRY (J. PHILLIPPs. v 

